Mix crumbs and butter; press firmly onto bottom and 2 inches up side of 9-inch springform pan.
Place caramels and milk in small microwavable bowl. Microwave on HIGH 2 to 2-1/2 minutes or until caramels are completely melted when stirred, stirring after each minute. Stir in pecans. Reserve 1/2 cup of the caramel mixture for topping. Drizzle remaining caramel mixture evenly onto bottom of crust. Refrigerate 10 minutes.
Beat cream cheese, sugar and vanilla with electric mixer on medium speed until well blended. Add eggs, 1 at a time, mixing on low speed after each addition just until blended. Pour over caramel mixture in crust.
Bake at 325 degrees F for 1 hour 5 minutes to 1 hour 10 minutes or until center is almost set. Run knife or metal spatula around side of pan to loosen cake; cool before removing side of pan. Refrigerate 4 hours or overnight.
Top with reserved caramel mixture just before serving. Melt chocolate as directed on package; drizzle over cheesecake. Store leftover cheesecake in refrigerator.